In a receiving device, deterioration of communication quality of a desired signal caused by an interfering or jamming signal, and deterioration of communication quality of a desired signal caused by deterioration of the communication transmission path hinder normal reception. Duplication of the transmission path and comparison of the two information received in duplicate using the result to detect abnormalities has been proposed as a method of detecting the deterioration of communication quality.
However, in a method such as this, it is necessary to have a duplicated transmission path, thereby increasing the overhead, and there have been cases in which the transmission efficiency was poor.